Survey reveals best and worst retailers for Black Friday deals

Looking for the best Black Friday deals? A survey of more than 5,000 ads from the biggest 21 retailers will help you out.

Conducted by finance web site WalletHub, the survey reveals which stores will offer the biggest discounts and how much shoppers could save.

JCPenny has the highest average discount rate at 65 percent, WalletHub found. Costco had the lowest Black Friday discount rate at 21 percent.

If you're shopping for a particular item, such as clothing, WalletHub breaks down the best deals into categories, finding that jewelry is the best category for Black Friday shopping deals (58 percent discount) and electronics are discounted the least (30 percent discount.)

The overall average discount for the 21 retailers was 39 percent, so aim to purchase items at that discounted rate or higher.

According to Bankrate, 40 percent of Americans will skip the stores and shop online for Black Friday, but that's not the time to get the best deals. Cyber Monday, the online version of Black Friday, offers great deals via the world wide web and a recent Adobe shopping forecast found Thanksgiving Day will likely have the lowest online prices overall this season.

Here is the WalletHub list of retailers and their expected average discounts.